If you have multiple environments, environment isolation prevents resource types from leaking between your various environments. To use environment isolation, you’ll generate metadata files that Puppet can use in place of the normal Ruby resource type implementations.

In open source Puppet, enable environment isolation with the generate types command. In Puppet Enterprise, environment isolation is automatically provided by Code Manager. Environment isolation is not supported for r10k with Puppet Enterprise.

Preventing resource types leaks in multiple environments

If you use multiple environments with Puppet, you might encounter issues with multiple versions of the same resource type leaking between your various environments. This doesn’t happen with Puppet’s built-in resource types, but it can happen with any other resource types.

This problem occurs because Ruby resource type bindings are global in the Ruby runtime. Thus, the first loaded version of a Ruby resource type takes priority, and then subsequent requests to compile in other environments get that first loaded version.

Environment isolation solves this issue by generating and using metadata that describes the resource type implementation, instead of using the Ruby resource type implementation when compiling catalogs.

Note: Other environment isolation cases, such as external helper logic issues or varying versions of required gems, are not solved with the generate types command.

Agent logic is unchanged

Catalog compilation results are exactly the same whether you use the metadata-based version of the resource type or the Ruby implementation. The agent acting on the catalog continues to use the Ruby-based implementation. Because the agent uses one, and only one, version of the logic, isolation is not a problem for the agent.

Enable environment isolation in open source Puppet

With open source Puppet, enable environment isolation by running the generate types command:

On the command line, run puppet generate types --environment <envname> for each of your environments.

For example, to generate metadata for your production environment, run:

puppet generate types --environment production

Whenever you deploy a new version of Puppet, overwrite previously generated metadata with puppet generate types --environment <envname> --force.

Enable environment isolation with r10k

To use environment isolation with open source Puppet and r10k, generate types for each environment every time r10k deploys new code. (Environment isolation is not supported with r10k in Puppet Enterprise.)

Create and use a script that first runs r10k for an environment, and then runs generate types as a postrun command.

If you have enabled environment level purging in r10k, whitelist the resource_types folder so that r10k doesn’t purge it.

Results of generate types

When you run the generate types command, it scans the entire environment for resource type implementations, excluding the resource types shipped in core Puppet. For each resource type implementation it finds, the command generates a corresponding metadata file named after the resource type in the directory <env-root>/.resource_types.

It also syncs the files in the .resource_types directory so that:

Types that have been removed in modules are removed from resource_types.

Types that have been added are added to resource_types.

Types that have not changed (based on timestamp) are kept as is.

Types that have changed (based on timestamp) are overwritten with freshly generated metadata.

The generated metadata files, which have a .pp extension, appear in the code directory. (If you are using Puppet Enterprise with Code Manager and file sync, these files appear in both the staging and live code directories.) These generated files are read-only: do not delete them, modify them, nor use expressions from them in regular manifests.

Troubleshooting environment isolation

If generate types cannot generate certain types, if the type generated has missing or inaccurate information, or if the generation itself errors or fails, this can cause a catalog compilation error of “type not found” or “attribute not found”. These issues can also be caused by manual changes in metadata files, incorrect permissions, or incorrectly implemented resource types.